The invention relates to carburetor constructions, and more particularly to carburetors of the type having a through passage for air and an adjustable throttle slide at an intermediate position which varies the flow-through area and simultaneously adjusts the amount of fuel which enters the passage at that intermediate point and is mixed with the flowing air. More particularly, the invention is concerned with the construction of the slide and its coaction with the nozzle means to achieve thorough atomization of the fuel. The invention is also concerned with a choke arrangement for the carburetor.